The present invention relates to an optical body, a method for manufacturing an optical body, and a light-emitting apparatus.
As disclosed in JP 2010-190599A, for example, an optical body combining the waveguide phenomenon of light and a macro concave-convex structure is known as one type of optical body. Such an optical body is also called a light guide panel. A macro concave-convex structure is formed on the surface of one side of the light guide panel. Additionally, inside the light guide panel, light is incident from a light source provided on a side face of the light guide panel. Light incident inside the light guide panel, or in other words, internally propagating light, propagates inside the light guide panel while reflecting off the surface of the light guide panel (that is, the interface between the interior and the exterior of the light guide panel). After that, the internally propagating light reflects off the surface of the macro concave-convex structure, and is emitted from the surface on the other side of the light guide panel. In other words, in the light guide panel, light incident from the side face of the light guide panel is emitted from the surface of the light guide panel. The light guide panel is used as a luminous body used with any of various types of display apparatus, or as a luminous body used for illumination, for example. Examples of display apparatus in which a light guide panel is used include various types of LCDs (for example, local dimming LCDs), passive-type display apparatus, light ornament panels for amusement facilities, illuminated panels for advertising such as digital signage, and the like. In these display apparatus, by turning a light source on and off, an expression becomes possible in which light appears to float up from the sites where the pattern of the macro concave-convex structure is formed. Consequently, the region in which the macro concave-convex structure is formed becomes a light-emitting region. Depending on the shape of the light-emitting region, various designs (such as the numerals of a speedometer) are expressed.
Meanwhile, as disclosed in JP 2010-190599A, in the region where the macro concave-convex structure is not formed on the surface of the light guide panel, a micro concave-convex structure for reducing reflections of extraneous light is often formed. A micro concave-convex structure is a concave-convex structure in which the average cycle of concavities and convexities is lower than the visible light wavelength band.
Consequently, both a macro concave-convex structure and a micro concave-convex structure are often formed on the surface of the light guide panel. The method for manufacturing the light guide panel may be a method for producing a master whose surface shape is the inverse of the surface shape of the light guide panel, and transferring the surface shape of the master onto the base material of the light guide panel.